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Solar system upgrade

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  • Solar system upgrade

    Hi everyone, I am new around here but I already found tons of useful information: very cool!

    I would like to upgrade an about 25 years old simple off grid solar panel system (50W) on a hut in the mountains. It was originally built just for lighting, but now I would like to add some comfort. This place is used just during a few summer months and gets plenty of sun.
    The current system runs on 12V. The cable run between solar panel and controller is about 10m (33 feet), battery sitting right below the charger controller and the load is located another 10m away.

    Here are the system components I was planning to use:

    - Battery: 12V 180Ah(C5) 230Ah(C20) (replaced recently, so this I would like to keep it)
    - MPPT Controller: Epever Tracer 3120AN - (30 Amps)
    - Solar panel: 1x LG 340N1C-V5 - 340W (best price/performance ratio I could find locally)
    or Panasonic 1x VBHN330SJ47 - 330W
    - Inverter: Victron Energy 12/500 (220V, very efficient and with stand-by ECO functionality)
    - Refrigerator: Liebherr TP 1760 (small and very efficient, runs on 220V)

    The plan would to use the solar panel system for:
    - Lighting (all LED)
    - Refrigerator
    - Occasionally recharge the battery (BLi150) of the electric Husqvarna weedwacker
    - Recharge cell phones, music play (negligible load)

    From all my researches and studies I think everything should work fine together, but any input/opinion would be greatly appreciated.

    More specifically I do have a couple of questions:
    1) Generally speaking I was wondering whether I should favor panels with higher voltage (Panasonic, SunPower) and lower amps in order to reduce power drop between panel and MPPT? Or keeping a lower voltage "stresses" less the MPPT?
    2) Do you think the stand-by ECO mode can be used with the refrigerator? Even if doesn't constantly run the cooling process I'm afraid the controlling part of the refrigerator still needs to be powered and therefore the 6W needed by the inverter cannot be avoided. Am I right?
    3) As anyone long term experience with the Epever MPPT?
    4) Anything else I am missing?

    Attached are all the needed datasheets

    Thank you so much in advance. Any input is very much appreciated !

    - Mat

    Attached Files

  • #2
    You might look into the fridge/chest freezer type used by the RV people. There are for
    example 24VDC units that will eliminate the 24/7 inverter standby drain, and most likely
    will use a lot less energy total. Higher voltage certainly will make your wiring less
    difficult, a 24VDC system will need only 1/4 the amount of copper as a 12VDC system
    with the same wiring losses.

    The intermittent loads may not amount to many KWH, esp if most are done when the
    sun shines and avoid exercising (wearing out) your battery. Once the daily energy
    (KWH) need is worked out, you will need a battery capacity able to deliver several
    days worth in case of clouds. And a charging system capable of dealing with all that,
    maybe a few panels. A generator it the ultimate backup to prevent battery destruction.
    Any batteries left unattended with some load, will probably be found destroyed later.
    good luck, Bruce Roe